Biobased plasticizer and surface covering employing same

ABSTRACT

Described herein are biobased plasticizer compositions comprising a compound having the structure of Formula I: 
                         
wherein R is C 6 -C 18  alkyl; along with methods of making and using same.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/423,358, filed Mar. 19, 2012, the entirety of which ishereby incorporated by reference.

FIELD

The present invention relates to plasticizers and surface coverings.More particularly, the present invention relates to biobasedplasticizers and surface coverings plasticized with biobasedplasticizers.

BACKGROUND

Many plastic materials, including polyvinylchloride (PVC), have a widevariety of uses, including as surface coverings. For many applications,plastic materials can be made softer and more flexible through the useof plasticizers. In particular, phthalates have long been used asplasticizers in PVC and other plastics.

Phthalates, such as di-(-2-ethylhexyl)phthalate and butyl benzylphthalate have come under increased scrutiny for a variety of reasons,including their reliance on petroleum-based feedstocks for production.

Some plasticizers based on non-petroleum feed stocks are known,including those based on vegetable oils, including soy, castor oil, andacetyl tributyl citrate. Other non-petroleum plasticizers include thosederived from natural sugars, such as sorbitol and mannitol and thosethat are based on diesters of linear aliphatic hydrocarbons.

Generally, availability of non-phthalate and non-petroleum basedplasticizers would permit expanded and/or new utilities and performancein known and new applications.

It would be desirable to increase the available types of non-petroleumplasticizers and particularly to develop new non-petroleum basedplasticizers, including some that are useful in floor tiles and othersurface coverings.

A biobased plasticizer and a surface covering plasticized by a biobasedplasticizer that do not suffer from one or more of the above drawbackswould be desirable in the art.

SUMMARY

According to an embodiment, a biobased plasticizer includes an esterformed as a reaction product of a furan derivative selected from thegroup consisting of furoic acid, furfural and furfuryl alcohol reactedwith a carboxylic acid or an alcohol.

According to another embodiment, a biobased plasticizer includes anester formed as a reaction product of a biobased aromatic compound and abiobased aliphatic compound, the biobased aromatic compound and thebiobased aliphatic compound each being derived from a renewableresource.

According to another embodiment, a surface covering is plasticized witha composition comprising an ester formed as a reaction product of afunctionalized aromatic heterocyclic compound reacted with a carboxylicacid or an alcohol.

Other features and advantages of the present invention will be apparentfrom the following more detailed description of exemplary embodiments,which illustrate, by way of example, the principles of the invention.

DETAILED DESCRIPTION

In accordance with exemplary embodiments, biobased plasticizers andsurface coverings plasticized by biobased plasticizers are disclosed.Embodiments of the biobased plasticizers and/or surface coverings permituse of a non-petroleum based plasticizer in surface coverings and otherapplications, permit. plasticizers and/or surface coverings to bemanufactured partially or entirely from renewable resources, permitplasticizers to be used in place of phthalates and/or and otherplasticizers under increased scrutiny by consumers, permit acceptableperformance of plasticizers, or combinations thereof.

As used herein, the term “biobased” refers to being having at least onematerial derived from a non-petroleum source. Organic non-petroleumsources include, but are not limited to, plant oils extracted from plantseeds, such as castor oil, linseed oil, soy oil, tall oil (pine oil),tung oil, vernonia oil, lesquerella oil (bladderpod oil), cashew shelloil, or other plant oils rich in unsaturated fatty acids, corn, cornsugar, sugar cane, vegetable oil, oats, cellulose, starch, sugar, sugaralcohols, such as xylitol, sorbitol, maltitol, sucrose, glycol,glycerol, erythritol, arabitol, rebitol, mannitol, isomalt lattitol,fructose, or polysaccharides or monosaccharides originated fromcellulose, starches, sugars, or combinations thereof. Inorganicnon-petroleum sources include, but are not limited to, ground shellsfrom animals, such as sea shells, clams, coral, or combinations thereof.A composition or product is identifiable as being biobased by having acarbon signature, such as a radioactive C14 or C13 signature, indicatingthat all or a portion of the carbon is from a non-petroleum source (forexample, greater than about 5%, greater than about 25%, greater thanabout 50%, greater than about 90%, at about 100%, or any suitablecombination, subcombination, range, or subrange therein), whetherorganic, inorganic, or both, in contrast to a signature indicating thepresence of carbon from a petroleum source, such as oil or coal. In someembodiments including material from such non-petroleum sources, one ormore of the above non-petroleum sources are excluded from forming thebiobased product of component. In sonic embodiments, biobased componentsare also recycled, for example, having material recovered aspost-consumer or post-industrial waste utilized in the production of newproducts, such as, wood or plants, pecan shells, wood flour, saw dust,walnut shells, rice hulls, corn cob grit, or combinations thereof. Inother embodiments, biobased components are recycled by includingrecycled materials that are not biobased, such as, limestone, quartz,ceramic powders, glass, fly ash, concrete powder, sand, and combinationsthereof, so long as additional biobased components are included.

Biobased plasticizers in accordance with exemplary embodiments comprisean ester formed as a reaction product of a functionalized heterocycliccompound derived from a renewable resource and a carboxylic acid or analcohol to form an ester. Such compositions are useful for plasticizingsurface coverings, including flooring tiles and sheets, as well as othervinyl materials.

In some embodiments, the functionalized heterocyclic compound is a furanderivative, which can be derived from components of naturally occurringmaterials, thus being a renewable resource and a source of biobasedcarbon.

Suitable furan derivatives for use with exemplary embodiments includeacids such as furoic acid or furandicarboxylic acid. A particularlysuitable furoic acid includes 2-furoic acid, while a particularlysuitable furandicarboxylic acid includes 2,5-furandicarboxylic acid.Other suitable furandicarboxylic acids include, but are not limited to,3-furoic acid, 2,3-furandicarboxylic acid, 2, 4-furandicarboxylic acid,3,4-furandicarboxylic acid, 2,3,5-furantricarboxylic acid, and2,3,4,5-furantetracarboxylic acid.

In another embodiment, a biobased plasticizer uses a furan derivative inthe form of an aldehyde, such as furfural, as the functionalizedheterocyclic compound.

In yet another embodiment, the furan derivative compound used in forminga biobased plasticizer is an alcohol, such as furfuryl alcohol.

Plasticizers in accordance with exemplary embodiments are typicallyesters and formed as the reaction product of the functionalizedheterocyclic compound with a carboxylic acid or an alcohol, theselection of which depends upon the nature of the compound beingreacted. That is, alcohols are generally reacted with acids to form theester, while aldehydes and acids may be reacted with alcohols. Anysuitable alcohols or carboxylic acids may be used, although those havingin the range of about 6 to about 18 carbon atoms in the main chain aretypical. In embodiments in which alcohols are reacted with thefunctionalized heterocyclic compound to form plasticizers in accordancewith exemplary embodiments, the alcohols may be polyols and inparticular may be diols in sonic cases.

It will further be appreciated that in some embodiments, the alcohol orcarboxylic acid to be reacted with the furan derivative or otherfunctionalized heterocyclic compound may itself be a biobased component.As a result, the formed ester for use as a plasticizer may be entirelyor nearly entirely biobased. For example, biobased alcohols such as1,3-propanediol or 1,4-butanediol may be used as the alcohol reactantfor use in combination with furan derivates that are acids such asfuroic acid and furandicarboxylic acid. Similarly, renewable carboxylicacids, such as sebacic acid, succinic acid, adipic acid, and azelaicacid, may be employed as the acid reactant for use in combination withfuran derivatives that are alcohols.

Embodiments in which the functionalized heterocyclic compound is analdehyde (such as furfural) may be converted to the ester product foruse as a plasticizer directly by reacting the aldehyde with an alcoholin the presence of bromine or other catalyst to form the ester.Additionally or alternatively, the aldehyde may be directly esterifiedusing aluminum triethoxylate, with or without a catalyst. Alternatively,a two step process may be employed. In the first step, the furfural canbe catalytically converted to 2-furoic acid. Any suitable catalyst maybe employed, including potassium permanganate for example. The 2-furoicacid s further reacted with an alcohol in the presence of a catalyst,such as a strong acid, for example, to form the ester. The use of a twostep process may be preferred over the use of a one step process inwhich bromine is the catalyst as a result of the bromine's toxicity.

2-furfuryl alcohol may be converted to an ester in a one step reactionwith a suitable acid, such as sebacic acid, adipic acid, and azelaicacid, for example. The reaction may be catalyzed using a strong acid.

In one embodiment, 2-furoic acid is reacted with a bis-diol in thepresence of heat and a catalyst to yield an ester having the followingstructure:

In another embodiment, the bis-diol is replaced by polyols in thereaction. Exemplary polyols include, but are not limited to, aliphaticpolyether polyols and aliphatic polyester polyols, either of which caninclude components derived from renewable resources, such as biobased1,3-propanediol or 1,4-butanediol, sebacic acid, succinic acid, adipicacid, and azelaic acid.

In another embodiment, 2,5-furandicarboxylic acid is reacted with twoorganic alcohols (ROH and R′OH) to yield an ester having the followingstructure, where R and R′ may or may not be the same aliphatic carbonchange:

The presence of the functional groups at particular numerical positionsof the furan derivatives used as reactants can result in providingplasticizer compounds that are structural analogs to those formed withnon-renewable materials currently used in plasticizer formation having,for example, a benzoate or dibenzoate-type structure. For example, twofunctionalities at the 2,5 position of furandicarboxylic acid can beused to form a terephthalate analog when reacted with an alcohol asdescribed above, as can readily be seen in the following comparison:

In a like manner, two adjacent functionalities from the furan ring atthe 2,3 positions or the 34 positions of furandicarboxylic acid can beused to form an orthophthalate analog when reacted with an alcohol asdescribed above.

Unlike a phthalate, however, furandicarboxylic acid is derived fromrenewable resources, not from petroleum feedstock. It has the additionaladvantage of being more polar than phthalates and other similarcompounds and as a result may provide better solution as a plasticizer.In addition to increased solvation capability, the heteroatomic aromaticring of a furan-based material, may exhibit a lower rate of migrationfrom a plasticized article than the comparable phthalate or benzoate.The polarity of the ring provides increased opportunity forintermolecular bonding between the resin and the plasticizer, thusdecreasing the chance for migration away from the resin.

Similarly, an ester resulting from the reaction of furoic acid orfurfural with an alcohol results in a compound that has a structureanalogous to a benzoate, but also provides the benefit of being derivedfrom a renewable resource and thus providing a biobased plasticizer:

Although described primarily herein in terms of reactions usingrenewable heterocyclic compounds, other aromatics may be used in placeof such compounds, including lignin, porphyrins and amino acids. Forexample, a porphyrin may be reacted at a double bond with an oxidizingagent, such as OsO₄ or dilute KMnO₄, resulting, in a diol product, whichmay then be reacted with a carboxylic acid to produce a diester, whichmay be used as a plasticizer. Additionally or alternatively, aminoacids, which include a carboxylic acid group, may be reacted with analcohol to form the ester, analogous to a benzoate.

The surface coverings plasticized by the plasticizer may be any suitablesurface covering. For example, suitable surface coverings include, butare not limited to vinyl composition tile, luxury vinyl tile, othersuitable tile products, cushion vinyl, sheet products, or combinationsthereof.

EXAMPLES

The invention is further described by way of the following examples,which are presented by way of illustration, not of limitation.

Example 1

A biobased plasticizer was formed using 2-furoic acid. 120 g of furoicacid (commercially obtained from Pennakem) was reacted with 123.3 g, ofisooctyl alcohol in 70 mL of toluene and 1.2 g p-toluenesulfonic acid.The reactants were stirred under heat to dissolve the acid, then heatedto boiling during which 2-octyl furanoate (C₁₄H₂₄O₃) and water wereformed as reaction products. Because of an azeotrope formed by thetoluene solvent and the water by-product, the reaction was cooled anddried over magnesium sulfate to remove water, then filtered. The organiccomponents were then distilled under vacuum to separate the furanoateproduct. A clear liquid was obtained and its identity as 2-octylfuranoate was confirmed by FTIR.

Examples 2-6 and Comparative Example 1

The 2-octyl furanoate of Example 1 was then used as biobased plasticizerto formulate a floor covering composition and formed into tiles. Table 1provides five formulations used in creating tiles using, the plasticizerof Example 1 and a control formulation using a conventional phthalateplasticizers as a comparative example. In each case, 1 kg batches wereformed and the amounts in Table 1 reflect grams of each component.

TABLE 1 Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Solvin 550 GA 45.045.0 45.0 45.0 45.0 45.0 (PVC Resin) Formolon 608 71.0 71.0 75.0 71.071.0 71.0 (PVC Resin) Kronos 2210 10.0 10.0 10.0 10.0 10.0 10.0(titanium dioxide) Thermchek T843 2.3 2.3 2.3 2.3 2.3 2.3 (stabilizer)S-3100 (butyl benzyl 32.0 0 0 0 0 0 phthalate/ epoxidized soy oil)2-octyl furanoate 0 40.0 36.0 30.0 32.0 20.0 Di-propylheptyl 8.0 0 0 0 00 phthalate Dioctyl terephthalate 0 0 0 10 0 0 Di-isononyl 0 0 0 0 8.020.0 cyclohexanoate Limestone 823.7 831.7 831.7 831.7 831.7 831.7

The resulting compositions were processed into floor tiles and exceptfor a strong odor in nearly every case, generally demonstrate acceptableresults with respect to mill feed, roll tack, hot strength, blanketformation, moisture curl, and light stability, as shown in Table 2, andthat achieve the additional advantage of utilizing a biobasedplasticizer.

TABLE 2 Comp. Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 1 Mill Feed Good PoorGood Good Very Excellent Good Roll Tack Very Fair Good Fair GoodExcellent Good Hot Strength Very Fair Fair Fair Fair Excellent GoodBlanket Formation Excellent Good Fair Fair Fair Excellent Moisture CurlPoor Poor Fair Fair Good Good Response Light Stability Very ExcellentVery Excellent Good Fair Good Good

Example 7

A second biobased plasticizer was formed by reacting 286 g1,3-propanediol, 175 g isophthalic acid, 156 g phthalic anhydride, 151 gsebacic acid, and 24 g 2,5-furandicarboxylic acid in the presence of 0.4g dibutytin bis-lauryl mercaptide as catalyst (obtained as T-20 from AirProducts of Allentown, Pa.).

The foregoing illustrates some of the possibilities for practicing theinvention. Many other embodiments are possible within the scope andspirit of the invention. It is, therefore, intended that the foregoingdescription be regarded as illustrative rather than limiting, and thatthe scope of the invention is given by the appended claims together withtheir full range of equivalents.

The invention claimed is:
 1. A surface covering comprising: from about1.5 wt. % to about 5 wt. % of a biobased plasticizer compositioncomprising isooctyl 2-furoate; wherein the surface covering is selectedfrom: a tile product and a sheet product.
 2. The surface covering ofclaim 1, wherein the tile product is selected from a vinyl compositiontile and a luxury vinyl tile.
 3. The surface covering of claim 1,comprising from 3.2 wt. % to 3.6 wt. % of isooctyl 2-furoate.
 4. Asurface covering comprising: from about 1.5 wt. % to about 5 wt. % of abiobased plasticizer composition comprising a compound having thestructure of Formula I:

wherein R is isooctyl; wherein the surface covering is selected from: atile product and a sheet product; and wherein the compound having thestructure of Formula I is a reaction product of furoic acid and isooctylalcohol.
 5. The surface covering of claim 4, wherein the isooctylalcohol is derived from a renewable resource.
 6. The surface covering ofclaim 5, wherein the biobased plasticizer composition further comprisesat least one nonrenewable component.
 7. A surface covering of claim 6wherein the tile product is selected from a vinyl composition tile and aluxury vinyl tile.
 8. The surface covering of claim 1 comprising fromabout 2 wt. % ot about 4 wt. % of the biobased plasticizer compositioncomprising isooctyl 2-furoate.
 9. The surface covering of claim 4comprising from about 2 wt. % ot about 4 wt. % of the biobasedplasticizer composition comprising the compound having the structure ofFormula I.